Mechanism for clipping holes in sheet material



APPLICATION FILED MAY 13. 1918. i

- I Patented July 27, 1920.

2 SHEETS-SHEET 1.

INVENTOR WITNESSES= cwy ATTORNEY E. B. ALLEN.

MECHANISM FOR CLIPPING HOLES IN SHEET MATERIAL.-

APPLICATION FILED MAY 13. 1918. 1,347,486.

. Patented July 27, 1920.

2 SHEETS-SHEET 2.

INVENTOR- ATTORNEY of which the following OF BRIDGEPORT,

CONNECTICUT, ASSIGNOR TO THE SINGER MANUFACTURING COMPANY, A CORPORATION OF NEW JERSEY.

CLIPPING HOLES INSHEET MATERIAL.

Specification of Letters Patent.

Application filed May 13, 1918. Serial No. 234,132.

To all whom it may mm.-

Be it'known that I, EDWARD B. ALLEN, a citizen of the United States,- residing at Bridgeport, in the county of F airfield and State of Connecticut, have invented certain new and useful Improvements in Mechanisms for Clipping'Holes in Sheet Material, is a specification, reference being had therein to the accompanying drawings. 7

' This invention relates to and anvil devices for clipping holes in sheet material. More particularly, the invention is designed for use in buttonhole cutting and stitching machines wherein it' is customary to provide punch and anvil cutters fo'r cutting an eyed hole in fabric material while it is hcld by the work-clamps and prior or subsequent to the formation of the usual ove'rseaming stitches about the hole. WVhe'n thehole is cut, a small diskjof material is clipped from the leather or other fabric "material operated upon and it is iighly desirable that this cut-out piece of coacting punch material beimrn'ediately removed from the field ofoper'ations. r

In prior machines of the present type the cnttingedge of the punch, after a time, becomes somewhat rounded and smooth at the entrance to the usual punch-passageway and, as a result, the punch fails to cut the work 'clean even under excessive pressure and also fails to 'pick up the cut-out piece of material. Moreover, an incre'asejof punching pressure causes the punch to rapidlyw'ear; or form a groove in the anvil, thereby impairing its effectiveness since the punch tends to mash the last fibers to be cut into the groove of the anvil' without severing them. Consequently, when the punch is elevated, the'cut-o'ut piece hangs to the bodyof the work by a few mashed fibers. WVhen' such a cutter is used in connection with an automatically operated train of mechanism effecting the cutting and stitching of the button hole, this failare is a source of rut-out portion will be sewn into the button- .iole,'resulting. in imperfect work. Further, ;he cut-out portion will often cause deflec- ;ion or breakage of the stitching needle or ieedles. V

In the machine disclosedin my Patent o. 4735M, of April 26, 1892, use is made vf an: upwardly spring-pressed and autovided, within the greatannoyance'as the matically controlled ejector-pin for shooting the cut-out portion of material upwardly through the punch-passageway. This mechanism, however, is relatively complicated and costly to manufacture and is entirely unsuitable for embodiment in cut- Patented July 27, 1920.

termechanism which is adaptedto travel toward and from tlOIl. j V p The primary object of the present invention is to provide a punch-and-anvil cutting device of simplified construction which will cutthe work clean under a moderate pressure, pick up the cut-out disks of material with certainty after long continued use, and operate;repeatedly over long periods of timewithout attention on the part of the operator. I

A further object of the invention is to provide a punch-and anvil cutting mechanism which will cut a hole in buttonhole cutting posicourse to a complication of additional to the punch and anvil elements. Still further, the invention has for an object to provide a Work-holding and punching mechanism including punch and anvil cutters which will cut a clean hole in the work with an application of less cutting pressure than has heretofore been found necessary, thereby materially lessening the tendency of the cutter element to form the objectionable groove in the anvil element and consequently lengthening the life of said elements.

To these ends movable parts the anvil element is area defined by the eye of the cutter'ele'inent, wit-h a hump or protube'rance preferably constituted by the rounded head of a small lifter-plug, the reduced shank of which is forced into a hole drilled inthe center of the eye-portion of the cutting block or anvil. It has been found by experiment, that this hump or protuberance on the anvil causes the punch to invariably cut and pick up the clipping even when dulled through long continued use. This certainty of operation is probably due to the arching of the material into the mouth of the punch, causing the edges of the cut-out portion to tightly grip the sides of the punch passageway. It is also probable that the hump or protuberance of the present device, in shoving the column of clippings along the passageway,

pro-

sheet material and pick up the cutout piece without reas the cutter descends, relieves the reactionary pressure of the clippings which heretofore contributed to the failure-of the punch to pickup the newly formed clipping. Moreover, the hump or protuberance tends, during the cutting action, to strainthe fibers of the material against the edge of the cutter, thereby combining a sort of tearing action against the" cutting edge with the cutting action caused by direct pressure of into the mouth of the cutter, thereby cau s-' Iing such hump to tension the work within 1 the clampsprior to and during the cutting action' This arching" of the cut-out mate-. rial renders the area of the punching, when subsequently disengaged slightly greater than that of the discharge passage in the'punch, to which its edges thus cling in the separation of the cutting'ele ments so as to remain lodged therein for retraction-from the body-material. 'Anytendtically eliminated since the of the work by a few mashed'fibers is practendency of the strain imposed. upon the fibers by the hump is to break or'pull apart these fibers which are mashed or otherwise weakenedby the cutter.

In the accompanying drawings, Figure 1 is a horizontal section throughthe standard of a buttonholesewing machine embodying the invention,"showing the work-holding and buttonhole cutting mechanisms in plan. Fig. 2 is a side elevation of the parts shown in Fig. 1. Fig.3 is a side elevation of the punch-and-anvil cutting device used in the above machine. Fig. 4: is a transverse vertical'section through the punch and anvil ele ments in closed position. Figs. 5 and 6 are detail perspective views of the punch-andanvil elements, respectively. a

As illustrated, the invention is embodied in cutting or punching mechanism of the type described in my United States Patent No. 1,048,786 of Dec. 31, 1912, and commonly 'isecl in connection with buttonhole sewing machines for cutting the buttonhole in the work. Buttonhole cutting mechanism of this type commonly comprises upper and lower cutter-levers 1 and 2, respectively, ful- "crumed at 3 upon the traveling fulcrumblock 3 which, in practice,is shifted longi- 1 'tudinally of the bed of the machine to carry the cutters toward and from cutting position. The upper cutter-lever ,1;c arries the from the hump 'or protuberance and 111 flattened condition,

ency of the cut-out piece to hang to the body usual die or punch element 4 having, in the present instance, a sharpened straight edgeportion 5 o ning the sharpened edge-portion 6 which clips out the eye. of the buttonhole. Leading upwardly from the eye'- punching portion 6 is a passageway or chan nel 7 for the clippings. As shown in Fig. 4,- the walls at the lower end portion ofthe passageway up to the point 8 are substantially perpendicular to the plane of the cutting edge 6. Above the point 8 the walls of the passageway are slightly flared outwardly to permit free upward movement of the column 9 of clippings or punchings. The punch element t may besuitably dove-tailed into a block'lO mounted on thele ver 1 andheld in said block bya 'set-screw 11.

The cutter-block or anvil 12 comprises a preferably fiat surface '13 againstwhich the" cutter element A acts and is formed with a shank 14 which is fixed within a socket 15 in the lower cutter-lever 2 by a set-screw 16, the end of which bears against the flat surface-portion 17 of said shank.

The hump. or protuberance referred to maybe made integral with the anvil but is preferably constructed as follows ;-Drilled into'the eye-portion of the anvil 13 is a small 7 hole'18' into which is forced the shankof a. plug 19 having a rounded head 20 fixedly located within the eye-cutting portion and above the plane surface 13 of the anvil.

When the cutting elements l and 12 are closed uponthe work, 'the 2O arches the material into the mouth of the punchpassageway 7 and tends to shove the column I 9 of'clippings along the passageway. This arching of the material before it is cut results in the cutting out of a disk ofmaterial slightly larger than the hole in thepunch, which disk of material on account of its arched position will tend to grip the walls of the passageway and resist downward displacement;

v i It will be seen that the present device entirely obviates the use of movable plunger or ejector mechanism uch as. disclosed in my earlierpatent above referredto and is.

consequently cheap to manufacture and free from: ill effects of wear and tear. Moreover the present deviceis readily carriedby the usual cutter-levers and maybe moved with r the latter towardand from cutting position.

After punching mechanism of the present type has been in usefor a long time the cutting element 4 wears a groove in the surface of theanvilor cutter-block Band, to secure a clean cut, it eventually becomes necessary to dress or'file down the surface 13 of the anvil to obliterate the groove. When this operation isperformed tlie' plug 19 may bereadily driven from its seat and replaced in operative position as soonas the block 12'has been resurfaced. 7

Av punch-and-anvil cutter of the class described, the anvil element of which is formed with a'fixed hump withinthe area defined by the eye of the cutter-element, is particularly efficient when used in combination with means for clamping the work and holding it firmly clamped while it is being cut, so that the material will or placed under strain as the hump arches the material into the mouth of the cutter. Referring to Figs. 1 and 2, which illustrate the invention as embodied in a buttonhole sewing machine constructed substantially in accordance with the disclosure of my copending application Serial No. 41,884, filed July 26, 1915, 21 represents a portion of the hollow base from which standard 22 carrying the usual bracket-arm (not shown). Mounted upon the base 1 is the work holder, common to machines of this type and comprising laterally separable lower clamp-plates 23 upon which are mounted the fulcrum-blocks 24 for the clamping arms 25 carrying at their forward ends the pivoted clamping feet 26 adapted to grip the work against the clamp-plates 23 and cut away at 27 to expose the eyeletend of a buttonhole. Mounted in the fulcrum-blocks 24 are rock-shafts 28 connected together at their inner ends by the usual offsetpin-and-fork device 29 and carrying cam-projections, such as shown at 30, Fig.2, adapted to de press the wear-plates 31 sustained by the clamp-arnis 25 and close the clamping feet upon the work.

Fixed to one of the rock-shafts 28 rearwardly extending arm 32 over which is disposed the front end of the clamp-closing lever 33 fulcrumed at 34 to the bracket 35 fixed to the bed 21; 'The rear end oftlie lever 33 is acted upon by the usual clampclosing cam 36 carried by the cutter-shaft 37 which is journaled within and transversely of the standard 2 and is actuated through the usual onerevolution clutch device 38 from the constantly-running pulley 39. The rock-shaft 28 which carries the arm 32 also has fixed thereto a manually operable arm 10 by means of which the clamps may be closed, when desired, inclependently of the clamp-closing lever Springs, such as shown at 41, elevate the clamping feet whenthe shafts 28 are rocked to open the clamps.

The rearwardly directed arms of the cutter-levers 1 and 2 extend respectively, above and below the cutter-shaft 37 and are drawn into engagement with the usual cutter-closing cams 4:2 and 43 on the cuttershaft by means of the tension-spring 44 connected at its opposite ends to pins 45 and 46 projecting laterally from the cutterlevers 1 and 2, respectively.

The traveling fulcrum-block 3 carrying the fulcrum-pin 3 for the cutter-levers is be tensioned' rises the the substantially alined" slidably mounted in the usual manner upon the bed 1 and is connected by a link 47 with the usual cutteradvancing and retracting cam 18 fixed to the cutter-shaft. shown in Fig. 1, the cutters occupy a retracted position during the stitching of the buttonhole. In the present instance, when the cuttershaft is caused to execute its single rotation during the buttonhole-producing cycle, the cam 36 acts to close the clamps upon the work and the cam 18 advances the cutters to cutting position wherein they are thereupon closed upon the work between the clamping feet 26 by the action of the cams 42 and 13. After the buttonhole is cut the cam 48 withdraws the cutters to ineffective position.

The machine is-also preferably equipped with mechanism for spreading or separating the clamp-plates either before or after the buttonhole is cut. Such mechanism is preferably constructed substantially in accordance with thedisclosure of my copending' application Serial No. 180,737, filed July 16 1917, but may take any of the usual forms. Referring to F ig; i, it will be readily appreciated that if the work is gripped between the clamping elements 23 and 26 it will be tensioned during the descent of the cutter element 1 when the hump 20 arches the material into the mouth of the channel 9 7. The fibers of the material will therefore be under strain transversely of the direction of movement of the cutter element while the latter is acting. It is no doubt largely due to this condition that the present cutting mechanism produces a clean cut hole in the material with an application of much less pressure than has heretofore been found necessary. 7

From the foregoing description it will be obvious that the present improvement is particularly adapted to all operations involving the removal of sections of material preparatory to stitching or otherwise reinforcing the edges of the same, whether of keyhole shape, as in the usual form of eyelet-end buttonhole, or of circular or other hollow form as in the case of stitched or otherwise reinforced eyelets.

Having thus set forth the nature of the invention, what I claim herein is 1. A cutting device comprising an eyed cutting element having a passageway for the clippings, and an anvil having a surface against which the cutting element is adapted to act to cut a hole in the material, said anvil having a hump in fixed relation therewith and rising from the surface portion thereof withiii the area embraced by the eye of the cutting element when said eye is in contact with the anvil.

2. A cutting device comprising an eyed cutting element having a passageway for the clippings and an anvil having a surface against which the cutting element is adapted to act' to out a hole in the materiah'said anvil having a rounded hump in fixed relation therewith and rising from the surface portion thereof within the area embraced by the eye of the'cuttmg element when said eye is in contact with the anvll.

3. A cutting device comprlsingan eyed cutting element having a passageway for the clippings, an anvil having a surface against which the cutting element is adapted V to act to cut a hole in the materiaL-said anvil against which the cutting element is adapted having a-recess within-the surface vportion thereof embraced by the eye of the cutting element when said eye is m contact with the anvil, and a lifter-plug fixedly secured within said recess.

It cutting device comprising an eyed cutting element having a passageway for the clippings, an anvil having a surface against which the cutting element is adapted to act to cut a hole in the material, said anvil having a recess within the surface portion thereof embraced by the eye of the cutting element when said eye. is in contact With the anvil, and a lifter-plug driven into said recess. I

5. A cutting device comprising a cutting element having an eyed knife-edge and a passageway for the clippings, an anvil having a surface against which the knife-edge is adapted to act to cut a hole in the material, and means for arching the material into the passageway of the cutting element before the cutting action is completed.

6. A cuttingdevice comprising an eyed cutting element, an anvil having a surface to act to cut a hole in the material, said anvil having a hump rising from the surface portion thereof within the area embraced by the eye of the cutting element when said eye is in contact with theanvil, and Workholding-,means'with; which said hump co;

operates to tension the work while it is i i i being cut.

7. A cutting device comprising an eyed j cutting element, ananvllvhaving a surface 7 against which the cutting element is adapted to act to cut a ;hole in the'material, said anvil having ahump rising from the surface, portion thereof' wlthin the area embraced by the eye of the cutting element when said eye is in contact with the anvil, u

and enacting worlngripping devices with which said hump cooperates to stretch the work beforeand while it is being cut.

,8. VVork-holding andicutting mechanism comprising work-clamping elements, a, shaft for closing said elements upon the work,

cutting means including coacting cutter and anvil elements for cutting a hole inthe clamped work,-

7 and operative connections between said shaft and cutting means, said anvil element beingiprjovided with a hump Vforfarching the material into the-mouth of the cutting element during the cutting action.

9. Work-holding and cutting mechanism comprising,,in combination, coacting worlc clamping elements, coacting punch-and-i anvil cutting elements occupying an inopcr ative position remote "from the clamping elem'ents, means for relatively moving the D ARD B ALLEN 

